Main shaft fixture

ABSTRACT

A main shaft fixture for fixing a main shaft on a wind turbine during installation and repair work on heavy parts of the wind turbine nacelle, in the case where the fixture is formed of several sections for mounting on stable structural parts in the nacelle, including the nacelle&#39;s bottom frame. The main shaft fixture has adjustable pressure mandrels with tap shoes, which cause the fixture to be usable regardless of the turbine main shaft geometry, such that it can be mounted without fixing the rotor. The main shaft fixture also has facilities for mounting of a lightweight crane and a self-hoisting crane with a ground-based winch, respectively, as well as a rotor lock which, in combination with actuators of the main shaft fixture, enables the main shaft and the main shaft bearing to be sufficiently displaced vertically from its bearing in the nacelle to service or replace the bearing.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of U.S. patent application Ser. No.15/517,288 filed Apr. 6, 2017, which is a 371 of International PatentApplication No. PCT/DK2015/000040 filed Oct. 6, 2015, which claims thebenefit of priority to Denmark Patent Application No. PA 2015 00527filed Sep. 4, 2015, and to Denmark Patent Application No. PA 2014 00573filed Oct. 7, 2014, the contents of which are incorporated herein byreference in their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a main shaft fixture for the fixing ofa main shaft on a wind turbine during the execution of installation andrepair work in heavy parts of a wind turbine arranged in a nacelle onwind turbines, with the fixture being divided up into a number ofsections for installation on stable structural parts in a nacelle in awind turbine, including the nacelle's bottom frame.

Description of Related Art

During installation and repair work on the nacelle of wind turbinesthere is often a need to perform fixing of the main shaft of the windturbine, for example, with the replacement and servicing of a windturbine gear box, generator or with the replacement of its main bearing,or other heavy structural parts present in the nacelle of the windturbine. The stated components, which are mutually conjoined andanchored to the nacelle's bottom frame, are stable in an assembledstate, but when separation needs to be undertaken during repairs andservicing of the turbine, static instability and imbalance arises, whichcan lead to the turbine's structural parts being damaged, so that thereis a need to fix the wind turbine main shaft.

German Patent Application DE 102006013539 A1 (NORDEX ENERGY GMBH)discloses a main shaft fixture for fixing the main shaft on a windturbine during the execution of installation and repair work on heavyparts that are arranged in the nacelle on wind turbines, with thefixture being divided up into a number of sections for installation onstable structural parts that are found on a wind turbine nacelle,including the bottom frame of the nacelle.

Up to now it has been necessary to halt the turbine, i.e., brake it andfix the rotor with a rotor lock, and then mount an actual fixture tofirmly hold the main shaft, subsequent to which servicing of thecomponents in the wind turbine nacelle is able to take place. However,it is inappropriate to have to halt the operation of the wind turbinewhile the mounting of the main shaft fixture is taking place, as thestandstill of the wind turbine during the time that is spent to installthe fixture involves a not insignificant operating loss in the form of alack of energy produced (power). Furthermore, the known main shaftfixtures are relatively inflexible in relation to shaft geometry, whichmeans that in practice nearly just as many different fixtures need to bebuilt and stored as there are shaft geometries that exist, which isinappropriate. In addition, the use of self-hoisting cranes, whosewinches are placed on the ground surface near the turbine's tower, isincreasing, because the use of such involves large savings in the levelof expenses for servicing of wind turbines since the use of large mobilecranes for handling the above-mentioned large and heavy components ismade superfluous. This causes however a need for facilities foranchoring the self-hoisting crane with the ground-based winch in thenacelle. However, the self-hoisting winch requires furthermore thepresence of a lightweight crane, for the hoisting of snatch blocks,etc., that are to be anchored on/in the nacelle or on the blades of thewind turbine, which poses requirements concerning the facilities formounting the lightweight crane.

In the event of servicing in particular large wind turbines, it mayhowever be inappropriate to block the main shaft's rotation with anactual rotor lock, but rather be appropriate to simply retain the shaftin position and permit a certain rotation of the shaft, which ispossible by turning the blades/nacelle out of the wind so that the shaftvia the effects of the wind on the blades only rotates very slowly, ornot at all, whereby it is acceptable in terms of safety, to performservice work in the nacelle of the wind turbine concerned.

SUMMARY OF THE INVENTION

Thus, it is the purpose of the invention to specify a main shaft fixturethat provide a more universal application in relation to shaft geometry,which moreover does not require halting and fixing of the wind turbinemain shaft, but which may however comprise the means for such.

It is further the purpose of the invention to provide a main shaftfixture that in addition offers facilities for the mounting of aself-hoisting crane, with a ground-based winch.

It is by the invention realized that this is possible by a main shaftfixture of the nature specified in the introduction, which ischaracterized by that the main shaft fixture comprises at least threeradial displaceable pressure mandrels, substantially symmetrical locatedaround the center axis of the main shaft, the ends of said pressuremandrels facing the main shaft are furnished with a tap shoe, and saidpressure mandrels being displaceable between a passive, withdrawnlockable position where the tap shoes are configured to be located at adistance from the surface of the main shaft and an advanced lockableposition where the tap shoes are configured to be engaged with the mainshaft.

Considerable flexibility is hereby attained with respect to the mainshaft fixture's use for the fixing of main shafts with differentgeometries on wind turbines, since solely the degree of mobility of thepressure mandrels and the size of the main shaft fixture pose limitingfactors for the usability of such. The main shaft fixture is thus bothusable for fixing of cylinder-shaped shafts with different diameters andfor the fixing of shafts with conical shapes. The main shaft fixtureaccording to the invention is multi-part, and may be mounted onpermanent structural parts, preferably the bottom frame of the nacelle,while the rotor of the wind turbine is in operation.

With the intent of being able to use a self-hoisting crane with aground-based winch together with the main shaft fixture according to theinvention, it may comprise mounting facilities for a self-hoisting cranewhose winch is placed on the ground surface ground near the foot of thewind turbine.

The advance thereof is that the establishment of facilities for thefixing of the wind turbine's main shaft, as well as the establishment ofmounting facilities for the self-hoisting crane with a ground-basedwinch, take place simultaneously, which saves work processes, and space,which are of great importance, as the space in the nacelle in a windturbine are most often narrow, and furthermore the main shaft fixture aswell as the mounting facilities for a self-hoisting crane in the nacellenormally utilize the same permanent structural parts in the nacelle foranchoring.

With the intent of ensuring easy and rapid establishment of theself-hoisting crane, which requires the hoisting of snatch blocks withwires originating from the ground-based winch with a lightweight cranewhich is mounted on stable structural parts in the nacelle, the mainshaft fixture may comprise mounting facilities for a lightweight crane.

For the purpose of securing the rapid fixing of the main shaft using themain shaft fixture according to the invention, the pressure mandrels maybe provided with actuators for displacing and retaining the tap shoes inthe passive position and the active position, respectively,alternatively in a selectable position between the passive and theactive position.

Time is thereby saved in the displacement of the tap shoes between thepassive position, and the active position pressed against the mainshaft's surface.

In a more simple form of embodiment of the main shaft fixture accordingto the invention, the pressure mandrels may be comprised of threadedbolts whose free ends facing the main shaft are furnished with tapshoes, where the threaded bolts work together with threaded holes inrelevant sections of the fixture. The pressure mandrels with the tapshoes are hereby displaced by manual turning of the threaded boltsbetween the passive position and the active position.

With the intent of being able to permit rotation of the main shaftduring performance of servicing of a relevant wind turbine and in orderto protect the main shaft and the main shaft fixture, slide plates mayexist between the opposing sides of the main shaft's surface and the tapshoes.

This enables the main shaft to be fixed in its position by the mainshaft fixture, but with the main shaft being permitted to rotate withoutit being damaged due to the presence of the slide plates.

In a first embodiment of the slide plates, this could comprise the freeends of tap shoes facing against the main shaft being furnished withslide plates, which in the active extended position are engaged with themain shaft.

In a further embodiment, the main shaft fixture may according to theinvention comprise a multi-part slide plate working in conjunction withthe main shaft to be mounted on the main shaft, where the multi-partslide plate in its mounted state on the main shaft cooperates with thetap shoes.

This enables the tap shoes on the main shaft fixture's pressure mandrelto slide directly on the multi-part slide plate, in the event of apossible rotation of the main shaft caused by the effects of wind on theblades. The tap shoes on the main shaft fixture's pressure mandrels maycooperate with the multi-part slide plate on the main shaft, with orwithout slideway linings on the opposing sides of the tap shoes facingthe main shaft.

In a further embodiment of the main shaft fixture as per the invention,it may comprise a multi-part needle bearing, roller bearing, ballbearing, consisting of a, multi-part inner ring, fastened on the mainshaft, and a therewith cooperating multi-part outer ring consisting anumber of bowed sub segments according to the number of tap shoesmounted on the opposing side of the tap shoes facing the multi-partinner ring, which in the advanced active position of the pressuremandrels form the outer ring at a distance from the external peripheryof the multi-part inner ring, and where a suitable number of needlerollers, rollers or balls are placed between the inner ring and outerring, and where means are present for retaining the needles, rollers, orballs in position between the inner ring and outer ring.

An actual temporary bearing connection is hereby formed between the mainshaft fixture and the main shaft, about which the main shaft is able torotate.

With the intent of being able to fix the rotor on the wind turbine afterit has been braked to a stop, the main shaft fixture according to theinvention, may comprise a rotor lock, for fixing the wind turbine rotor.

In a preferred embodiment of the rotor lock, it is comprised of aflange, whose bolt circle geometry corresponds to a bolt circle geometryon the rotor, said flange element being fastened at the ends to thefirst end of two first beam-shaped brackets extending parallel with, andon each side of the main shaft, said beam shaped brackets belonging tothe main shaft fixture, and where the other end of the brackets arepivotally mounted with horizontally oriented bolt connections, on otherbrackets belonging to the main shaft fixture, which are anchored on thebottom frame of the nacelle.

It is hereby achieved that the rotor can be fixed by introducing a boltthrough one or more of the overlapping holes in the bolt circles on theflange fastened to the bottom frame and the bolt circle on the rotor,respectively.

With the intent of being able to perform replacement of the shaft's mainbearing, without being forced to dismount the main shaft, the main shaftfixture may furthermore comprise at least a second actuator, between thenacelle's bottom frame and the opposing side of the first beam-shapedbrackets facing such and the nearest rotor lock, where the otheractuator is movable between a first passive outer position and an activeouter position whereby the flange element is moved vertically.

This enables the main shaft to be able to be raised from its bearinghanging in the rotor lock, such that the main bearing of the shaft canbe replaced or serviced without the necessity of removing the shaft fromthe nacelle.

The invention is explained in further detail in the following withreference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of parts of a wind turbine nacelle,presenting the nacelle bottom frame, the wind turbine main shaft, and amain shaft fixture according to the invention, with a lightweight craneand a self-hoisting crane mounted,

FIG. 2 is a more detailed perspective view from another angle of what isshown in FIG. 1, where the main shaft is made transparent, presentingthe pressure mandrel with tap shoe belonging to the main shaft fixtureaccording to the invention,

FIG. 3 is a more detailed perspective view from another angle of what isshown in FIG. 1, presenting the actuators for raising the main shaft,where the main shaft is made transparent,

FIG. 4 is a detailed perspective view of the main shaft fixture for awind turbine, where the tap shoes and the main shaft are furnished withslide plates, and

FIG. 5 is a detailed perspective view or the main shaft fixture for awind turbine, where the slide plates are replaced by a multi-part needlebearing/roller bearing/ball bearing formed of a multi-part inner ringfastened to the main shaft and a therewith cooperating multi-part outerring consisting of bowed sub-segments of the number of tap shoes mountedon the opposing side of the tap shoes facing the inner ring.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a bottom frame 2 in a nacelle (not shown) on a wind turbine(not shown), where the main shaft 4 of the turbine, with a gear box 6and a rotor 8, and where the main shaft fixture 10 according to theinvention is shown in the mounted state, bearing a lightweight crane 12and a self-hoisting crane 14 with a ground-based winch (not shown),respectively. The bottom frame 2 has for reasons of clarity been madetransparent.

In the illustrated embodiment, the main shaft fixture 10 is anchored tothe bottom frame 2 near the gear box 6 and near the rotor 8, andcomprises a multi-part frame 14, which together with a cross member 16fastened on it encloses a part of the main shaft 4 between the rotor 8and the gear box 6. The multi-part frame 14 is anchored on the bottomframe 2.

FIG. 2 shows what is seen in FIG. 1, but in an end view, seen from therotor side of the shaft 4, and where the rotor 8 for reasons of clarityhas been made transparent. As it appears from FIG. 2, the multi-partframe 14 and cross member 16 comprise in total four pressure mandrels 18symmetrically placed around the main shaft 2, with tap shoes 20 that areengaged onto the main shaft 4 in order to fix it in place.

The pressure mandrels 18 may be comprised of hydraulically drivenpistons whose free ends comprise the tap shoes 20, but may also beexecuted in other manners, where they are moved manually between theactive position where the tap shoes 20 are engaged with the main shaft 4and the passive, withdrawn position.

As it appears from FIG. 3, the main shaft fixture 10 comprises twoparallel passing first beams 22, one on each side of the main shaft 4.In first ends of each first beam 22 nearest to the rotor 8, a rotor lockis fastened in the form of a flange element 24, the hole circle geometry26 of which is similar to the hole circle geometry 28 of the rotor 8over part of the periphery of the rotor. For locking of the rotor 8, theholes 7 in the rotor 8 and the holes 9 in the flange element 24 arebrought to overlap, and subsequently, bolts are inserted through theoverlapping holes, which are tightened with nuts, after which the rotor8 is fixed/locked by the flange element 24.

The other end of the parallel passing first beams 22 (that nearest tothe gear box 6) are pivotally anchored on horizontally oriented bearingbolt 30, on a bracket 32, which is fastened to the bottom frame 2. Theparallel passing first beams 22 are mutually connected with second crossmembers 34, on which bracket facilities 23 are seen for a self-hoistingcrane 14 with a ground-based winch (not shown).

As it appears in FIGS. 1 & 3, an actuator 36 is located between thebottom frame 2 and the parallel passing first beams 22. Activation ofthe actuator 36 will result in a change of the distance between thebottom frame 2 and the first beams 22, in which the flange element 24 issuspended, which will cause the flange element 24 and the rotor 8 andthereby the main shaft 4 to be raised, which will result in thepossibility to replace the main shaft's bearing 38 without the necessityof hoisting the main shaft 4 down to the ground, which is quitetime-saving when the main shaft bearing 38 has to be repaired orreplaced.

In FIG. 1, it is moreover shown how the main shaft fixture 10 comprisesmounting facilities 40 for the lightweight crane 12.

FIG. 4 shows an embodiment of the main shaft fixture according to theinvention, which is specially suited for use for fixing the wind turbinemain shaft 4 in position on the nacelle, but where rotation of the mainshaft 4 is possible, in the active position of the pressure mandrels/tapshoes (18, 20), engaged with the main shaft.

As shown in FIG. 4, a slideway 42, 44 is located between the opposingsides of the tap shoes 20 facing the surface of the main shaft 4.

The slideway may be comprised of slide plates 42 that are fastened tothe opposing free ends of the tap shoes 20 facing the main shaft 4,which in their active advanced position are engaged with the main shaft4, but which alternatively may comprise a multi-part slide plate 44cooperative working with the main shaft 4, for mounting on the mainshaft 4, said multi-part slide plate 44 in its mounted state on the mainshaft 4 cooperates with the tap shoes 20. It must be stated that thepresence of the multi-part slide plate 44 on the main shaft 4 does notnecessarily exclude the presence of the slide plates 42 and the tapshoes 20.

In a further embodiment, the main shaft fixture 10 is comprised of amulti-part needle bearing/roller bearing/ball bearing 46, formed of amulti-part inner ring 48 fastened on the main shaft as well as, acooperating multi-part outer ring 50 formed of bowed sub-segments 52equal to the number of tap shoes mounted on the opposing side of the tapshoes 20 facing the inner ring 48, which in the advanced position of thepressure mandrels form the outer ring 50 at a distance from the outerperiphery of the multi-part inner ring 48, and where an appropriatenumber of needle rollers, rollers, or balls 54 (in the shown embodimentrollers 54) are arranged between the inner ring 48 and the outer ring50, and where means (not shown) are present for retaining theneedles/rollers or balls (54) in position between the inner ring 48 andouter ring 50.

The means mentioned for fastening of needle rollers/rollers/balls 54 maybe formed of cooperating edge delineators in opposing sides of the innerring 48 and the outer ring 50, alternatively as a means for holdingbetween which the needle rollers/rollers/balls 54 are fastened.

The presence of the slide plates 42, 44, alternatively the multi-partneedle bearing, roller bearing, ball bearing 46, involves the main shaft4 being permitted to rotate simultaneously with it being fixed in itsposition during servicing of the wind turbine, which can serve a purposenamely for larger wind turbines.

The inventor has recognized that the main shaft fixture 10 can assumeother embodiments than disclosed in the preceding and shown in thefigures, however such do not change the inventive aspect that iscomprised of specifying a main shaft fixture 10 of the given type thatcomprises adjustable pressure mandrels 18 with tap shoes 20, whichcauses the fixture 10 to be usable regardless of the geometry of themain shaft 4 on a wind turbine, and thus that such can be mountedwithout fixing the rotor 8 in place, and furthermore of combining themain shaft fixture with facilities 40 for mounting of a lightweightcrane 12 and a self-hoisting crane 14 with a ground-based winch,respectively, as well as a rotor lock 24 and finally of furnishing themain shaft fixture 10 with actuators 36, enabling the main shaft 4 andthe main shaft bearing 38 to be raised sufficiently from its bearing inthe nacelle that it can be serviced or replaced.

What is claimed is:
 1. A self-hoisting crane comprising: mountingfacilities for mounting to a lightweight crane, a winch located on aground surface near a foot of the wind turbine, and a main shaft fixturefor fixation of a main shaft on a wind turbine during execution ofinstallation and repair work on heavy parts of a wind turbine, thefixture being divided up into a number of sections for mounting onstable structural parts in a wind turbine nacelle including a bottomframe of the nacelle, wherein the main shaft fixture comprises at leastthree independently, radially displaceable pressure mandrels for fixingof cylinder-shaped shafts with different diameters and for the fixing ofshafts with conical shapes, the pressure mandrels being substantiallysymmetrical located around a center axis, first ends of said pressuremandrels, in use, facing the main shaft and being furnished with a tapshoe, wherein said pressure mandrels are displaceable between a passive,withdrawn lockable, position where the tap shoes are configured to belocated at a distance from the surface of the main shaft and an advancedlockable position where the tap shoes are configured to be engaged withthe main shaft, in use, said tap shoes enabling the main shaft to befixed in position by the main shaft fixture while being permitted torotate.
 2. The self-hoisting crane according to claim 1, wherein thepressure mandrels (18) are provided with actuators for displacing andretaining the tap shoes (20) in the passive position and the activeposition, respectively, or in a selectable position between the passiveand the active position.
 3. The self-hoisting crane according to claim1, wherein the pressure mandrels (18) are comprised of threaded boltshaving opposing free ends that face the main shaft and are furnishedwith tap shoes (20), and wherein said threaded bolts cooperate withthreaded holes in respective sections of the fixture (10).
 4. Theself-hoisting crane according to claim 1, wherein slide plates (42, 44)are located between the opposing sides of the surface of the main shaftand tap shoes.
 5. The self-hoisting crane according to claim 4, whereinthe slide plates are configured so that the opposing free ends of thetap shoes (20) facing the main shaft (4) are provided with a one of theslide plates (42) which in an active advanced position is engaged withthe main shaft (4).
 6. The self-hoisting crane according to claim 5,wherein one of the slide plates is a multi-part slide plate (44)cooperating with the main shaft (4) for mounting on the main shaft (4),where the multi-part slide plate (44) in a mounted position on the mainshaft (4) cooperates with the tap shoes (20).
 7. The self-hoisting craneaccording to claim 1, further comprising a rotor lock (24) for fixationof the rotor (8) of the wind turbine.
 8. A self-hoisting crane with amain shaft fixture (10) for fixation of a main shaft (4) on a windturbine during execution of installation and repair work on heavy partsof a wind turbine, where the fixture (10) is divided up into a number ofsections for mounting on stable structural parts (2) in a nacelle in awind turbine, including the bottom frame (2) of the nacelle, wherein themain shaft fixture (10) comprises at least three radially displaceablepressure mandrels (18), substantially symmetrical located around acenter axis (11) of the main shaft, first ends of said pressure mandrels(18) face the main shaft (4) and are furnished with a tap shoe (20), andwherein said pressure mandrels (18) are displaceable between a passive,withdrawn lockable position where the tap shoes (20) are configured tobe located at a distance from the surface of the main shaft (4) and anadvanced lockable position where the tap shoes (20) are configured to beengaged with the main shaft (4), further comprising a rotor lock (24)for fixation of the rotor (8) of the wind turbine, further comprisingone of a multi-part needle bearing, roller bearing, or ball bearing (46)comprised of a multi-part inner ring (48) fastened to the main shaft(4), and a therewith cooperating multi-part outer ring (50) comprised ofbowed sub-segments (52) corresponding to the number of tap shoes,mounted on the opposing side of the tap shoes (20) facing the inner ring(48), which in the advanced active position of the pressure mandrelsform the outer ring (50) at a distance from the outer periphery of themulti-part inner ring (48), and where a plurality of needle rollers,rollers, or balls (54) are arranged between the inner ring (48) and theouter ring (50), and where means are present for retaining the needles,rollers, or balls (54) in position between the inner ring (48) and outerring (50).
 9. The self-hoisting crane according to claim 8, wherein mainshaft fixture (10) is connected by mounting facilities (40) the crane(12).